Digestive enzymes are produced by the salivary glands, glands in the stomach, the pancreas, and glands in the small intestines. For example, digestive enzymes produced by the pancreas and secreted into the stomach and small intestine aid in digestion. Digestive enzymes produced by the pancreas are secreted into the duodenum, or upper segment of the small intestine, where the pH is around 5 to 6, and the enzymes assist in the digestion of food components, including carbohydrates, lipids, proteins and nucleic acids. However, when digestive enzymes are administered orally, the enzymes are exposed to highly acidic conditions in the stomach, with a pH of around pH 1-2, as well as gastric proteases which denature and degrade the enzymes.
Digestive enzymes have been administered to mammals to treat enzyme deficiencies caused by conditions affecting the pancreas, such as pancreatitis and pancreatic enzyme deficiency. Pancreatic enzymes administered to humans are commonly of porcine origin. Manufacturers of enzyme preparations have also used enteric coatings for lipase compositions in individuals with cystic fibrosis who require administration of lipases. The preparations for lipase delivery have used enteric coatings containing, for example, hypromellose phthalate, dimethicone 1000, and dibutyl phthalate.
Certain methods for coating sensitive bioactive substances have been described. U.S. Pat. No. 6,261,613 to Narayanaswamy et al. discloses particles that can contain yeast, coated in a shell of a fat in a beta prime form (i.e., triglyceride crystals having a blocky symmetry). The coating material can further contain emulsifiers such as those found in hydrogenated vegetable oil. However, the coating only allows release of the yeast in a limited temperature range of about 40° C. to about 55° C. U.S. Pat. No. 6,251,478 B1 to Pacifico et al. discloses certain sensitive substances including certain bioactive compounds encapsulated in a lipid material.
No description in the Background section should be taken as an admission that such disclosure constitutes prior art to the instant invention.